1. Field of the Invention
The invention relates to a weighing device for a packaging machine.
2. Description of the Prior Art
DE 100 01 068 C1 has already disclosed a device for metering and dispensing powder into hard gelatin capsules or the like. As tamping pins descend into bores, they compress the powder, which is to be packaged, into pellets. In order to be able to obtain information about the mass of the pellets, means are provided that detect the spring path of the tamping pin directly preceding the ejecting pin.
In the capsule filling machines currently in use, usually the capsules are weighed after being filled, i.e. the combined weight of the capsule and filling (gross weight) is determined in order to check whether the filling quantity is correct. There are several methods for accomplishing this, e.g. weighing with a scale, weight determination through other physical effects, etc. using the statistical method. This method is imprecise due to a significant variance in weight of the empty capsules. There are also known methods in which the net weight is determined by a gross minus tare calculation. In these methods, capacitive physical effects are used, an approach that involves significant inaccuracies that are contingent on the system.
The object of the present invention is to eliminate or at least mitigate the above-mentioned disadvantages.